The point of your post ? Is it necessary ? Or are you just one of those people who is perfect at everything ? Furthermore I hope your grammar mistakes where intentional as your sentence is no better...

No need to be perfect, but at least try and make your post understandable.

1. Is it one storey house or double +, will affect the cost of building it.
2. Are you planning to have small lounge/tv room/dining room or a big entertainment area/lounge/dining room?
3. How big will the kitchen be? Will it be open kitchen or closed?
4. Are you also going to have a patio?
5. How many bathrooms?
6. Any storerooms for your junk?
7. Will you need a study for taking work home to do or studying?
8. How big will passages be? If they arent wide enough it could feel cramped.
9. Also think of the positioning of the bedrooms, best to have most of them facing east for a nice sunny wake up call.

I may be wrong, but judging by the OP's nick, I will hazard a guess that his first language isn't english.
So to all the lame-ass posters complaining about the spelling & grammar, let's see you post your next reply in zulu/xhosa/sotho.

I would say that you could probably work safely on R3500 /mē, as long as you aren't looking for luxurious finishes and fittings.

I bought a site at illovu and it look big 324 square meter
and i need to build 181 sqm size of the house.but i want to know how many block will use to build this house?

That depends on a few things:
1) The height of the walls - walls go all around you house and use lots of blocks. The easiest way to save blocks is to make the walls lower. If your family isn't very tall you should not make the walls higher than 1.5m. Some guests might have to bend down or crawl, but it might be worth it considering all the blocks saved.
2) The no of rooms - you should keep the no of rooms to a minimum. Rooms need walls and walls need blocks (as already mentioned)
3) The colour - if you intend on painting you house blue/purple you will need to buy some excess blocks as the blue/purple colouring will cause some blockss to fail. Any other colour shouldbe better and save some blocks.

So all in all it depends on your choices. But if "I have to make a rough guess 200 blocks should do it.

That depends on a few things:
3) The colour - if you intend on painting you house blue/purple you will need to buy some excess blocks as the blue/purple colouring will cause some blockss to fail. Any other colour shouldbe better and save some blocks.